NO-SLOT-CLOCK PATCH

Why is this patch needed?

SMT does have a new utility disk that will allow use of the
No-Slot-Clock without modifying ProDos that will work with all versions
of ProDos past, present and future - (A new SYSTEM file is installed
and executed automatically on boot).  However, I found that in my
situation, booting from a hard disk with an 8mhz Zip Chip installed on
my Apple IIe, it did not work unless the Zip was first reset to 1mhz
(ug!) - so I have continued to update the ORIGINAL No-Slot-Clock
Install program to avoid this problem.

How to make the patch to the software originally provided by SMT.

The text file NSC.PATCH should be copied onto a BACKUP of the original
No Slot Clock software disk and executed from BASIC.  Make sure the
prefix is set to /NO.SLOT.CLOCK, that the INSTALL program is present,
and type -NSC.PATCH to EXEC the text file and modify the install
program.  This patch will fix the original NSC INSTALL program to work
with ProDos 2.02 and earlier versions.  If you have previously modified
INSTALL with earlier versions of this patch, it will still work since
lines 157-159 are replaced with this new code. It is a modification of
a patch that appeared in the 2/90 A2-Central by Frank Shirk which was
subsequently remodified by me to work with subsequent versions of
ProDos and now is being re-remodified to work with 2.02. (Whew!).

Modifying ProDos to work with the No-Slot-Clock.

To modify ProDos, run the STARTUP program from the /NO.SLOT.CLOCK disk
and select the menu item to apply the modification to ProDos. This
loads the INSTALL program and a binary file containing the NSC clock
driver).  If the program does not recognize the version of ProDos being
modified, or if the modification has already been made it will abort,
unceremoniously.

Version 2.02 of ProDos is very similar to 2.01 as far as this patch is
concerned.  A one byte offset was required to place the 4 byte patch at
the right location.  Maybe one day Apple will stop changing the
locations of the clock routines in ProDos. (Wishful thinking.)

For the curious, the modification for ProDos 2.02 consists of a one
byte change to $2E06, the clock driver at $2F00 is replaced with the
NSC driver and another 4 byte change is required at $2851. The patched
INSTALL program checks various locations in ProDos to determine the
ProDos version and applies the patch accordingly.  Those of you with
Block Warden can follow the patches by subtracting $2000 from the above
memory locations.  Thus, $2851 is relative block $0851 in the F(ollow)
file mode of Block Warden.

In case there are any enthusiastic attorneys are out there, I make no
guarantees for this patch for any purpose.  Use this patch at your own
discretion and always use backups.  This patch is freeware and must be
distributed with this file and without charge, other than a nominal
charge for media distribution.  ProDos is a copyrighted product of
Apple Computer Inc, Apple is a registered trademark of Apple Computer,
Inc; No-Slot-Clock is a copyrighted product of SMT, Inc.  Block Warden
is a part of the PROSEL utilities package, copyrighted by Glen E.
Breedon.  Prices slightly higher west of Maine, offer void where
prohibited by law or during full moon.


Nigel Broder February 14, 1993